Chap. XIII. 
VOCAL MUSIC. 
51 
cither then exert a choice, or the battle must be re- 
newed. So, again, with one of the Field-starlings of 
the United States (Sturnella ludoviciana) the males 
engage in fierce conflicts, but at the sight of a female 
they all fly after her, as if mad.”^^ 
Vocal and instrumental Music . — With birds the voice 
serves to express various emotions, such as distress, fear, 
anger, triumph, or mere happiness. It is apparently 
sometimes used to excite terror, as with the hissing 
noise made by some nestling-birds. Audubon relates 
that a night-heron (Ardea nycticorax, Linn.) which he 
kept tame, used to hide itself when a cat approached, 
and then suddenly start up uttering one of the most 
frightful cries, apparently enjoying the cat’s alarm 
^^and flight.” The common domestic cock clucks to 
the hen, and the hen to her chickens, when a dainty 
morsel is found. The hen, when she has laid an egg, 
repeats the same note very often, and concludes with 
the sixth above, which she holds for a longer time ; 
and thus she expresses her joy. Some social birds 
apparently call to each other for aid ; and as they flit 
from tree to tree, the flock is kept together by chirp 
answering chirp. During the nocturnal migrations of 
geese and other water-fowl, sonorous clangs from the 
van may be heard in the darkness overhead, answered 
by clangs in the rear. Certain cries serve as danger- 
signals, which, as the sportsman knows to his cost, are 
well understood by the same species and by others. 
The domestic cock crows, and the humming-bird chirps, 
in triumph over a defeated rival. The true song, how- 
Audubon’s ^ Ornitholog. Biography;’ on Tetrao cupido, vol. ii. 
p. 492 ; on the Sturnus, vol. ii. p. 219. 
' 25 ‘Ornithological Biograph.’ vol. v. p. 601. 
2^ The Hon. Dairies Barrington, ‘Philosophy Transact.’ 1773, p. 252. ] 
E 2 
